Delay action fuse



July 1l, 1950 M. s. KHARASCH ETAL DELAY ACTION FUSE 2 Sheets-Sheet l Filed March 22, 1946 wua/wto/r/s Morris. E Khara ch Fr ank H WEEH-Lemer.

July u, 1950 M. s. KHARASCH Erm. 2,534,499

DELAY ACTION FUSE Filed March 22, 194e 2 sheets-sheet z Kramm/wann' 30 1 a!!5g!!@wwwwfvwvwm 2Q MnrrE 'E Kharach Frank H Weshemer awww# Patented July l1, 1950 UNITED STATES @SENCE DELAYY ACTION FUSE Morris; S. Kharasch and Frank H. Westheimen. Chicago, Ill., assignorsto thefUnitedStatesof Americaas represented byt-hasecretary of. War

Application March 22, 1946; SerialNo; 656,461

This invention relates to an improved delayaction fuse and more particularlytov a delay action inga watch or clock mechanism by means of which the operation ofithe fuse can be accurate- Iyregulated. and which is so constructed that the possibility4 of the failure of' the fuse tofunction isl practically' eliminated.

Another object of the inventionE is to provide a fuse of the above described' character which is of a very compact construction and which can be made waterproof so that'ithe fuse can function in a submerged position` fordetonating a submerged charge of explosive, and which is also capa-ble of being set and armed' after having been connected to the explosive and while in a submerged' position.

A further object ofthe invention is to provide a fuse capable of being quickly, accurately and safelyl setV and armed and which is so constructed' that it is incapable of functioning for a predetermined time interval after the fuse has been armed.

Another object ofthe invention is to provide a fuse having safety means for arming the fuse, after it has been attached to the charge to be detonated andl set for the delayed action, which having once been armed is lockedV against movement to a position to disarm the fuse.

Other obiects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, which illustratev a preferred embodiment thereof, and' wherein-Z Figure 1 is a top plan view showing the fuse disarmed;

Figure 2 is a top planr View, partly in section, or the fuse and with certain of the parts removed;

Figure 3 is a transverse sectional view taken along the line 3 3- of Fig. 1;*

Figure 4 is a view similar toFig. 2' and; showing theA fuse parts in released positions;

6 Claims. (Cl. 1.02-82l Figure Slis-:a sectional view of a portion of the fuse; andi Figure! Sfis an. enlarged cross sectional view or' a partV of' the fuse taken substantially alonga. i plane asindicated'by theline 6,-6 of Figure 5.

Referring more-A particularly to the drawings;

wherein like, reference characters designate like'.y

or corresponding parts throughout the several views; 1:' designates. generallye the improved mechanical fuse. in7 itsA entirety and which includ'esf housing 8 formed of a body portion 9 and a transparent',cover` l0,`which is securedv to the body: portion 9; byscrew tastenings l I'. The bodyJ portion 9 is preferably formed" integral and maybe ofI any material' such .as av suitable plastic, and providedvii-thi a-n interior chamber |'2 which isk closed byI they transparentY cover I0: A watch meclranism;l designated generally I3, is containedk within the housing @and the driving mechanism thereof', not shown, isrdisposed within a recess, not shown, in the soit iron plates It' and I5; which serve to shield'the driving mechanism from external magnetic fields'. The driving mechanism' has-not been illustrated and will not be described since it' may be of' a conventional construction controlledi byfa knob I6 connected' to a shaft lli, byr' means of which the driving mechais wound' and set in a conventional manner'. An arbor' or shaft I8 is driven by the Watch driv- `ing mechanism and Ais` suitably geared thereto s0 as to make one revolution approximately every 30ror3-2A hours. A disk I9" is keyed' to the arbor I8 andl is provided with a notch 20 in its periphery. An indicating pointer 21"- is secured to the uppersurface ofthe disk I9- 'and is disposed be,

tween corresponding studs 212 which project uptrai opening L55 above the disk lll; Around'v the opening 251 the upper surface of the plate 23 is suitably inscribed with time interval calibrations 26. The distance between adjacent markings of the calibrationsv equal. the distance of' the move-` ment of thepointer 2 l' and disk I'9 during a period of onefhour. Thel disk |29 isl driven in a counter-y clockwise direction and as: clearly illustrated in Fig'. 2', the leading portion of the notchl 20' is defined by a substantially radially disposed edge, for a purpose whichy will hereinafter become apparent.

Abarrel or tubular housing 211 is containedl in' and extends acrossf one end of the. housing 81 and is provided with abone 28 which extends therethrough; 'and which isuclosed' at. one end by a threaded plug 29. The opposite end of the bore 28 is enlarged and internally threaded to receive and mount a percussion cap holder 30 which is provided with a restricted threaded end for detachably engaging in said threaded end of the bore 28. The holder 30 is provided with a bore which extends therethrough and its restricted portion 3I .contains a restricted bore portion 32 in which is mounted a percussion cap 33, the head of which is disposed at the inner end of the portion 3I. A metal washer 34 is mounted between the head of the percussion cap 33 and the inner end of the threaded portion of the bore 28 until such time as the fuse 1 is prepared for use, when said washer'34 is removed. A firing pin or striker 35 is slidably mounted in the bore 28 and is provided vwith anvelongated body portion 36 having a restricted intermediate portion 31 including an annular rearwardly inclined or frusto-conical portion 38. An expansion-` coil spring 38 is disposed betweenf'the plug 29 and the adjacent end. of the firing pin 35 for resiliently urging the firing pin toward the percussion cap 33, and said ring pin, at its leading end, is provided with pointed projection 40 arranged to strike and detonate the percussion cap" 33 when the firing pin is projected by spring 39.

-The upper metal plate I4 projects beyond the cover 23 to provide a supporting base member fora sear lever 4I and a trigger 42. Sear 4I is pivotally mounted at one end thereof at 43 on the plate I4. The intermediate portion of the sear 4I extends through a longitudinally'disposed slot 44 in the barrel 21 and one longitudinal edge thereof is provided with an enlargement 45 which extendsA into the recess 31 of the firing pin 35. The enlargement 45 is provided with a beveled edge 48 which bears against the frusto-conical' portion 31 to retain the firing pin 35` in a retracted position against the action of spring 39, as best seen 'in Fig. 2. The trigger 42 is ypivotally connected, intermediate of its ends at v41, to the plate I 4 and is provided with an arm 48 vwhich lextends toward the sear 4I and which normally has its free end bearing against the free end of the sear 4I, as clearly illustrated in Fig. 2, for retaining the sear in engagement with the firing pin 35. A contractile coil spring 49 is anchored at one end to base 'I4 and is connected at its opposite end to thesear 4I for yieldably urging the sear portion 45 out of engagement with the firing pin. The other arm 50 of the trigger 42 is disposed at Aanangle to the arm 48 and'is shaped to define a pawl which terminates in a pointed bill which normally bears against the periphery of the disk I9 and which is shaped to i-lt into the notch 20. A contractile coil spring I1is anchored at one end thereof to the base I4 and is connected at its opposite end to a laterally projecting arm 52 of the trigger 42 for urging the pawl 50 inwardly relative to the disk I9 and for urging the detent arm 48 outwardly and out of engagement with the free end of the sear 4I. The engagement of the bill of the pawl 50 vwith the periphery of the disk I9 normally retains the arm 48 in engagement with the sear 4I to retain these parts in a cocked position, as best illustrated in Fig. 2. A stop 53 projects upwardly from the base I4 and is disposed to be engaged by the arm 48 to prevent an inward movement of said arm beyond its position of Fig. 2.

'Ay bushing 54 extends through one sidewall of the housing 8 andA is provided with a bore 55 which extends therethrough. The bushing 54 is provided with an enlargement or head 58 at its inner end and which is disposed within the housing 8. A shaft 51 extends through the bore 55 of the bushing 54 and slidably and turnably engages the restricted inner end of the bore 55 and is provided with an enlarged outer end portion 58 which is threaded to engage the enlarged internally threaded outer endofthe bore 55. The shaft 51, at its outer end, is provided' with a knurled knob 59. Shaft 51, adjacent its inner end, is provided with spaced annular grooves 60 and 6I. As best seen in Figs. 3 and 5, a block 62 is provided with a dovetailed slot 63 which extends lengthwise-theretlirough and which opens outwardly of one side thereof and which is sized to receive the outermost groove E0 and the head 64 on the inner end of the shaft 51, for swiveling the shaft 51 to the block 62. The block 62 is disposed over the exposed portion of the metal base block I5 which protrudes from one edge of the upper metal block vI4-as best shown at Figure 3. A pin 65 projects from the block 82 parallel with shaft 51 and into a bore 6B in the block I4, and slidably fits said bore to limit motion of block 62 to translation in the direction of the axis of shaft 51. A stop pin 61 is secured to and projects from the block B2 parallel with shaft 51 and pin 65, and as best seen in Fig. 3, extends through and slidably engages a bore 68 in the cover 23 and, when in a projected position, as seen in Figs. l, 2, and 3, has its free end disposed in the path of movement of the studs 22. The head 56 is provided with an outwardly 'opening peripheral groove 69, as best seen in Fig. 6, containing a split spring ring 10 which engages the outer 'end of a locking pin 1I, which is slidably mounted in a radial bore 12 of the head 56. The pin 1I normally bears against the shaft 51 and is held thereby in a retracted position against the action of the spring ring 10, as seen in Fig. 2. However, when the shaft 51 is fully retracted, as seen in Figs. 4, 5, and 6, the pin 1I is projected inwardly by the spring 1I! into the groove 8|, which is then disposed to receive the pin, for locking the shaft 51 'to prevent inward axial movement thereof'` The fuse parts are in the positions as seen in to the charge, not shown, to be detonated by the' The knurled knob I 6 is operation of the fuse.

then pulled outwardly for setting 'the mechanism of the watch I3, and from its position of Fig. l, disk I9 is turned bythe setting operation'in a clockwise direction to set the pointer 2| at the indicia representing the desired number of hours after which the fuse 1 is intended to function after being set. The knurled knob- I5v `is then pushed inwardly, to its position of Fig. 1, and

turned in a conventional manner for winding' the driving mechanism of the watch. The block 82 is disposed in its forward position during-this operation, in engagement with the intermediate portion of the arm 48 to prevent said arm from retracted, the disk I9 cannot rotate sufficiently in a, counterelockwise' direction to position the" notch 20 to receive the'bill of the pawl 50, thus .providing a dual positive safety for retaining the fuse.; 1f in adisarmed, c onditicin.` 'Ihezfusc 1. isi

larmed-LL and; ready; to operate, byv turning the knurledfknob; 5.9 in a. counterclockyvise direction. for; retracting. shaft; 51, block; 62 and the stop pin 61 to,- fully arm the-fuse The knurled knob 59;` is turned; suiiioiently tofully. retract shaft 51 so; that .the-locking pin 1| Will engage the groove (ily to hold shaft51' against, inward axial move ment, toV prevent the fuse` 51, once armed, from beinggdisarmed. 'i3-he driving mechanism of the watch I3 turns the disk I9 in a counterclockwise direction until it moves beyond its position of Fig., 1 and to its. position.v of Fig. 4, at which time thelnotch 2liy will be disposed so-that the billof the pavvlv 50 will drop in to said notch, and, aspreviously mentioned, the leading edge of the notchl issubstantially-radially disposed so that thefbill of -the pawl 5B Willridegover the outer end of the notch and be projected immediately into the-notchbythe spring 5I. This will cause the trigger dito be rocked from, its position of Figs. l and` 2 tov its position. of- Fig. 4, to thus move the arm 48. out. of engagement with the free end of the Sear 4l to permit the spring 49 to pull the sear 4| away from'the barrel 2.1 to release the firingp pin 35. Firing0 pin 35 will be projected by thesDrng 39'so that the pointedl projection 40 will forcibly strike and detonate the primer 33 to thereby detonate-the charge connected to the holderl 30. If desired, theY spring 49 can be omitted and the coacting cam surfaces 38 and 46 Willfunction, due to the pressure exerted by the, spring 39, to retract the sear QI and release thefiring pin 35.

As seen. in Fig. l, when the stoppin 61 is disposed in. its` fully projected, operative position, it will-,engage one of the studs 22 at a point at which the, disk Iii still has a travel of. a distance that requires approximately one hour before the notch is disposed toI receive the pawl 50. Consequently, the Watch mechanism I3 cannot be set, when the safety means is in anY operative position, so that the fuse will function as soon as the safety means is moved to an inoperative, arming position. By providing the locking pin 1I, the fuse 1, once armed, is rendered incapable of being disarrned, so that the fuse must be detached from the charge or destroyed in order to prevent it from functioning. The fuse housing 8 can be made Waterproof so that the fuse can be submerged and set and armed While thus positioned. The entire operation of setting and arming the fuse is accomplished by operation of the knurled knobs I6 and 5S from the exterior of the fuse housing and the setting of the watch mechanism I3 can be observed through the transparent cover IIJ. The soft metal container, formed by the blocks I4 and I5, in addition to preventing the Watch mechanism from being effected by magnetic fields, also renders the operation of the mechanism substantially silent. The threaded connection of the shaft 51 with the bushing 54 prevents accidental Withdrawal of the safety.

Various modications and changes are contemplated and may obviously be resorted to, without .departing from the spirit and scope of the invenn tion as hereinafter defined by the appended claims, as only a preferred embodiment thereof has been disclosed.

We claim:

1. In a delay action fuse, a housing, a springurged firing pin slidably mounted in said housing, a, sear in said housing pivotable on a first axis from a first position engaging and holding said pin retracted, to a second position releasing simultaneously engaging said disk to positively..` prevent its movementinto saidy one position, said,

safety member being moyableyto a second posi?, tionl to vsimultaneously; free; said triggerf anddisk, andv spring meansgurging Said, searand trigger, into their. second-` positions.

2. A; delay act-ion fuse compri sing A ahousing?, a cloclnvorkin said housing, including a rotatif-.1,A able disk, having notch in its periphery, a.

trigger; pivoted on an axis in` said housingand` having first and second angularly related4 arms.. extending radially of saidV axisysaid first-armi having. a` noseadaptedto drop insaiclnotchirrl one position of said disk, a sear pivoted insaid.

housing, the pivotaxes of saiddisk, trigger andl Sear being` parallel; .a ringpin slidable .inn said. housing, a spring urgingrs aidpinfroni retracted to ring position, saidf Sear.- being adapted in a;

first position to hold;V said pin in retractedI posiu tion` and to release; saidy pin; when moved to a. second position, the; second armA of said triggery engaging 4and holding said searinits first. posi-`r mounted in said housing.- and. adapted in one`- position to simultaneously.l engagey and;l hold said.V

trigger against movement; releasingl said sear` and to engage the` abutmenton, said; diskto pre.- vent said notch from moving under said nose, means operable externally of said housing to withdraw said safety means from engagement with said trigger and disk, and means within said housing automatically operable to lock said safety means in Withdrawn position.

3. In a delay action fuse, a housing, a springurged ring pin slidably mounted in said housing, a scar in said housing pivotable on a rst axis from a first position engaging and holding said pin retracted, to a second position releasing said pin, a time-controlled disk rotatable in said housing, a trigger pivoted in said housing and having an arm adapted, in a rst position of said trigger, to engage and hold said sear in its said first position, yand in a second position of said trigger, to release said sear, said trigger and disk having means co-operating to permit movement of said trigger to its second position when said disk is in one position of rotation only, and to maintain said trigger in its first position at all other times, safety means movably mounted in said housing, said means engaging and holding said trigger in its first position, and simultaneously preventing movement of said disk to its said one position, said safety means being movable to a second position to simultaneously free said trigger and disk, spring means urging said sear and trigger into their second positions, said safety means including a block slidably mounted in said housing and adapted in safety position to engage and hold said trigger in rst 7l position, arl abutment extending from said block having its end interposed in the path of an abutment on said disk, and means manually operable from the exterior of said housing for sliding said block out of its said safety position, to .simultaneously free said trigger and disk.

4. A fuse as recited in'claim 3, said manually operable means comprising a shaft slidably and rotatably mounted in an aperture in the Wall of said housing and having a circumferential groove and a portionwithinsaid housing, a swivel connection between said blockv and shaft, and spring lock means within said housing adapted to engage in Asaid groove and lock said shaft when said shaft has been operated to move saidblock out of its safety position.

5. A'fuse `as recited in claim 3, said manually operable means comprising ya shaft threaded Vthrough a wall of said housing and having a circumferential groove in a portion within said housing,-a swivel connection between said block vand the adjacent end of said shaft, and a springjpressed plunger within said housing and adapted to engage in said' groove and thereby lock said shaft against axial movement when said l.block has been withdrawn from said safety position.

l6. "A delay action fuse comprising a housing, :a clockwork in said housing, including a rotatable disk having a notch in its periphery, a trigger pivoted on an axis in said housing and having first and second angularly related arms extending radially of said axis, said first arm having a nose adapted to drop in said notch in one position of said disk, a sear pivoted in said f housing, the pivot axes of said disk, trigger and sear being parallel, a firing pin slidable in said housing, a spring urging said pin from retracted to 'firing position, said sear being adapted in a first position to hold said pin in retracted position .and to release said pin when moved to a second position, the second arm of said trigger engaging and holding said sear in its first position when saidnose engages the periphery'of` said disk, a spring urging the nose of said trigger,-

against the periphery of said disk, an abutment on said disk, and safety means movably mounted in said housing and adapted in one position to simultaneously engage and hold` said triggerl against movement releasing said sear and to engage the abutment on said disk to preventv said notch from moving under said nose,means ed through one wall of said housing and having a circumferential channel within said housing,

a swivel connection between said safety means and said shaft, and means kin said housing cooperating with said channel to lock said shaft: to thereby maintain said fuse in armed condition. i

FRANK H. WESTHEIMER.

REFERENCES CITED The following references are of record in theA file of this patent:

UNITED STATES PATENTS Number Name Date 173,01'7 Jopling Feb. 1, 1876 289,642 Giles Dec. 4, 1883 854,977 Baker May 28, 1907 1,242,501 Wilhelm et a1. oct. 9,"1917 1,572,436 King Feb. 9, 1926 1,640,165 Varaud Aug. 23, 19,27 2,438,438 Hammond Mar. 23, 1948 2,485,949 Wilson Oct. 25, 1949 FOREIGN PATENTS Number Country 'Date Germany July 31, 1919 

